.signal4-reveal {
    display: none;
}
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    min-height: 100vh;
    padding: 20px;

    background:
        radial-gradient(
            circle at 50% 0%,
            rgba(39, 70, 91, 0.18),
            transparent 42%
        ),
        linear-gradient(
            180deg,
            #070c11 0%,
            #05090d 55%,
            #030609 100%
        );

    color: #d9e2e8;
    font-family: Arial, sans-serif;
}

body::before {
    content: "";

    position: fixed;
    inset: 0;

    pointer-events: none;

    background:
        repeating-linear-gradient(
            0deg,
            transparent 0,
            transparent 3px,
            rgba(255, 255, 255, 0.014) 4px
        );

    z-index: 50;
}


/* COMMON */

button,
input {
    font-family: inherit;
}

button {
    cursor: pointer;
}

button:disabled {
    opacity: 0.45;
    cursor: default;
}

button:active {
    transform: translateY(1px);
}


/* SIGNAL 01 */

.terminal {
    position: relative;

    width: min(850px, 100%);
    min-height: 0;

    margin: 30px auto;

    padding: 38px;

    background:
        linear-gradient(
            145deg,
            rgba(12, 25, 35, 0.98),
            rgba(6, 13, 19, 0.98)
        );

    border: 1px solid #294250;
    border-radius: 7px;

    box-shadow:
        0 18px 45px rgba(0, 0, 0, 0.4),
        inset 0 0 35px rgba(50, 100, 125, 0.025);
}

.terminal::before {
    content: "SIGNAL 01 // INCOMING";

    position: absolute;

    top: -8px;
    left: 22px;

    padding: 2px 9px;

    background: #071018;

    color: #597483;

    font-family: monospace;
    font-size: 8px;
    letter-spacing: 2px;
}

.system {
    color: #657f8d;

    font-family: monospace;
    font-size: 11px;

    letter-spacing: 2px;
}

.terminal h1 {
    margin-top: 28px;

    color: #e6eef2;

    font-size: clamp(44px, 7vw, 60px);
    letter-spacing: 7px;
}

.creator {
    margin-top: 9px;

    color: #6b8490;

    font-family: monospace;
    font-size: 13px;
}

.signal {
    position: relative;

    margin-top: 28px;

    padding: 30px;

    background:
        linear-gradient(
            135deg,
            #0b1821,
            #081118
        );

    border: 1px solid #2d4856;
    border-left: 3px solid #587a89;

    border-radius: 5px;

    box-shadow:
        inset 0 0 25px rgba(50, 100, 125, 0.035);
}

.signal::after {
    content: "TRANSMISSION";

    position: absolute;

    top: 14px;
    right: 18px;

    color: #3d5966;

    font-family: monospace;
    font-size: 8px;
    letter-spacing: 2px;
}

.signal p {
    margin-bottom: 10px;

    color: #607a88;

    font-family: monospace;
    font-size: 10px;

    letter-spacing: 3px;
}

.signal h2 {
    color: #c8dce5;

    font-family: monospace;
    font-size: 27px;

    letter-spacing: 5px;
}

.clue {
    margin-top: 25px;

    color: #9aadb7;

    font-family: monospace;
    font-size: 13px;

    line-height: 1.8;
}

.terminal input {
    margin-top: 22px;

    width: 68%;

    padding: 14px 15px;

    background: #050b10;

    border: 1px solid #2e4855;
    border-radius: 4px;

    color: #e4edf1;

    outline: none;
}

.terminal input:focus {
    border-color: #6c8b9a;

    box-shadow:
        0 0 14px rgba(70, 120, 145, 0.1);
}

.terminal input::placeholder {
    color: #506773;
}

.terminal button {
    margin-left: 7px;

    padding: 14px 21px;

    background: #13232d;

    border: 1px solid #466270;
    border-radius: 4px;

    color: #d0dfe5;

    font-family: monospace;
    font-size: 10px;

    letter-spacing: 2px;

    transition: 0.2s;
}

.terminal button:hover {
    background: #1a303c;
    border-color: #7895a2;
}

#result {
    margin-top: 20px;

    color: #8aa7b5;

    font-family: monospace;
    font-size: 12px;

    line-height: 1.6;

    white-space: pre-line;
}

.hint-info {
    margin-top: 15px;

    color: #536d79;

    font-family: monospace;
    font-size: 9px;

    letter-spacing: 2px;
}

#continueBtn {
    display: none;
}


/* SIGNAL 02 */

.signal-02 {
    position: relative;

    width: min(760px, 100%);

    margin: 30px auto;

    padding: 40px;

    background:
        linear-gradient(
            145deg,
            #12161a,
            #0b1014
        );

    border: 1px solid #3a464c;
    border-radius: 7px;

    box-shadow:
        0 18px 45px rgba(0, 0, 0, 0.45),
        inset 0 0 35px rgba(170, 180, 185, 0.018);
}

.signal-02::before {
    content: "SIGNAL 02 // RECOVERED";

    position: absolute;

    top: -8px;
    left: 22px;

    padding: 2px 9px;

    background: #0b1014;

    color: #707e85;

    font-family: monospace;
    font-size: 8px;

    letter-spacing: 2px;
}

.signal-02::after {
    content: "ARCHIVE // 02";

    position: absolute;

    top: 20px;
    right: 22px;

    color: #4a565c;

    font-family: monospace;
    font-size: 8px;

    letter-spacing: 2px;
}

.signal-02 .small-text {
    margin-bottom: 25px;

    color: #707e85;

    font-family: monospace;
    font-size: 10px;

    letter-spacing: 4px;
}

.signal-02 h1 {
    margin: 0 0 30px;

    color: #e5eaed;

    font-size: clamp(38px, 6vw, 50px);

    letter-spacing: 4px;
}

.signal-02 .message {
    margin-bottom: 8px;

    color: #a4adb2;

    font-family: monospace;
    font-size: 14px;

    line-height: 1.8;
}

.signal-02 .message b {
    color: #dce4e7;
}

.signal-02 button {
    margin-top: 27px;
    margin-left: 0;

    padding: 13px 27px;

    background: #181e22;

    border: 1px solid #59666d;
    border-radius: 4px;

    color: #d7dfe2;

    font-family: monospace;
    font-size: 10px;

    letter-spacing: 3px;

    transition: 0.2s;
}

.signal-02 button:hover {
    background: #252d32;
    border-color: #a0abb0;
}

#source-area,
#number-area,
#next-area {
    display: none;
}


/* SIGNAL 03 */

.signal-03 {
    position: relative;

    width: 100%;
    min-height: 100vh;

    padding: 35px 7vw 100px;

    overflow: hidden;

    background:
        radial-gradient(
            circle at 82% 12%,
            rgba(38, 73, 94, 0.2),
            transparent 28%
        ),
        radial-gradient(
            circle at 12% 75%,
            rgba(23, 48, 65, 0.16),
            transparent 30%
        ),
        linear-gradient(
            145deg,
            #060a0e,
            #04070a
        );

    color: #d8e0e6;
}

.signal-03::before {
    content: "";

    position: fixed;
    inset: 0;

    pointer-events: none;

    background-image:
        linear-gradient(
            rgba(140, 175, 190, 0.035) 1px,
            transparent 1px
        ),
        linear-gradient(
            90deg,
            rgba(140, 175, 190, 0.035) 1px,
            transparent 1px
        );

    background-size: 50px 50px;
}

.signal-03::after {
    content: "03 // UNKNOWN LOCATION // TRACKING ACTIVE";

    position: absolute;

    top: 20px;
    right: 7vw;

    color: #4e6876;

    font-family: monospace;
    font-size: 9px;

    letter-spacing: 3px;
}

.signal-03 > * {
    position: relative;
    z-index: 2;
}

.signal-03 h1 {
    max-width: 900px;

    margin-top: 95px;

    color: #e9eef1;

    font-size: clamp(58px, 10vw, 120px);

    line-height: 0.83;

    letter-spacing: -6px;
}

.signal-03 .small-text {
    color: #607987;

    font-family: monospace;
    font-size: 10px;

    letter-spacing: 4px;

    text-transform: uppercase;
}

.signal-03 .message {
    max-width: 610px;

    margin-top: 20px;

    color: #81919b;

    font-family: monospace;
    font-size: 13px;

    line-height: 1.8;
}

.signal-03 .signal-box {
    position: relative;

    width: min(700px, 100%);

    margin-top: 75px;

    padding: 42px;

    background:
        linear-gradient(
            135deg,
            rgba(11, 28, 41, 0.9),
            rgba(6, 13, 19, 0.94)
        );

    border: 1px solid #2c4350;

    box-shadow:
        16px 16px 0 rgba(15, 25, 32, 0.65),
        0 0 35px rgba(40, 90, 115, 0.05);
}

.signal-03 .signal-box::before {
    content: "+";

    position: absolute;

    top: -9px;
    left: -9px;

    color: #718b98;

    font-size: 16px;
}

.signal-03 .signal-box::after {
    content: "SIGNAL_03";

    position: absolute;

    right: 18px;
    bottom: 12px;

    color: #3e5662;

    font-family: monospace;
    font-size: 8px;

    letter-spacing: 3px;
}

.signal-03 .riddle {
    margin: 32px 0;

    color: #d0d9de;

    font-family: monospace;
    font-size: 18px;

    line-height: 1.9;
}

.signal-03 input {
    width: 100%;

    margin-top: 20px;

    padding: 16px 0;

    background: transparent;

    border: none;
    border-bottom: 1px solid #425865;

    border-radius: 0;

    color: #e4edf1;

    font-family: monospace;

    outline: none;
}

.signal-03 input:focus {
    border-bottom-color: #9ab0bb;
}

.signal-03 button {
    margin-top: 20px;
    margin-left: 0;

    padding: 13px 27px;

    background: transparent;

    border: 1px solid #536e7b;
    border-radius: 0;

    color: #c0d0d7;

    font-family: monospace;
    font-size: 10px;

    letter-spacing: 3px;

    transition: 0.2s;
}

.signal-03 button:hover {
    background: #16242d;
    border-color: #91aab6;
}

.signal-03 #riddleResult,
.signal-03 #equationResult,
.signal-03 #equation2Result,
.signal-03 #cityResult,
.signal-03 #locationResult {
    margin-top: 20px;

    color: #718996;

    font-family: monospace;
    font-size: 11px;

    letter-spacing: 1px;
}

.signal-03 .hint-info {
    margin-top: 30px;

    color: #526d7a;

    font-family: monospace;
    font-size: 9px;

    letter-spacing: 3px;
}


/* SIGNAL 03 SECTIONS */

#equation-area,
#equation2-area,
#location-area,
.mini-stage,
#memory-stage,
#signal03-final {
    position: relative;

    width: min(850px, 100%);

    margin-top: 105px;

    padding-top: 45px;

    border-top: 1px solid #263943;
}

#equation-area::before,
#equation2-area::before,
#location-area::before,
.mini-stage::before,
#memory-stage::before,
#signal03-final::before {
    content: "SIGNAL DATA";

    position: absolute;

    top: -7px;
    left: 0;

    padding-right: 12px;

    background: #05080b;

    color: #506a76;

    font-family: monospace;
    font-size: 8px;

    letter-spacing: 3px;
}

.signal-03 .equation {
    margin: 40px 0;

    color: #dce7ec;

    font-family: monospace;

    font-size: clamp(30px, 6vw, 65px);

    letter-spacing: 5px;
}


/* LOCATION */

#location-area {
    min-height: 300px;

    padding: 45px;

    background:
        linear-gradient(
            135deg,
            rgba(17, 34, 45, 0.82),
            rgba(5, 10, 14, 0.92)
        );

    border: 1px solid #2b4452;

    box-shadow:
        12px 12px 0 rgba(10, 18, 23, 0.7);
}

#location-area .message:nth-child(2) {
    margin: 40px 0;

    color: #e3ebef;

    font-family: monospace;

    font-size: clamp(40px, 8vw, 90px);

    letter-spacing: 7px;
}


/* SHIBUYA GAME */

.game-area {
    width: min(850px, 100%);

    margin-top: 105px;
}

.game-area::before {
    content: "[ CONNECTION TEST // SHIBUYA ]";

    display: block;

    margin-bottom: 20px;

    color: #607b87;

    font-family: monospace;

    font-size: 10px;

    letter-spacing: 2px;
}

.game-title {
    display: inline-block;

    padding: 8px 12px;

    background: #101a20;

    border-left: 3px solid #718b96;

    color: #dce6ea;

    font-family: monospace;

    font-size: 24px;

    letter-spacing: 3px;
}

.game-info {
    max-width: 650px;

    margin: 15px 0;

    color: #667d87;

    font-family: monospace;

    font-size: 10px;

    line-height: 1.8;
}

.game-stats {
    display: inline-flex;

    gap: 25px;

    margin: 10px 0 18px;

    padding: 7px 10px;

    background: #05090c;

    border: 1px solid #263b45;

    color: #637a85;

    font-family: monospace;

    font-size: 9px;

    letter-spacing: 2px;
}

.game-stats b {
    color: #d4e0e5;
}

#game-board {
    position: relative;

    width: 100%;
    max-width: 760px;

    height: 420px;

    overflow: hidden;

    background:
        linear-gradient(
            180deg,
            #080e12,
            #05090c
        );

    border: 1px solid #415964;

    box-shadow:
        8px 8px 0 #020304;
}

#game-board::before {
    content: "";

    position: absolute;

    inset: 0;

    background-image:
        linear-gradient(
            #1d3039 1px,
            transparent 1px
        ),
        linear-gradient(
            90deg,
            #1d3039 1px,
            transparent 1px
        );

    background-size: 25px 25px;

    opacity: 0.35;
}

#game-board::after {
    content: "";

    position: absolute;

    left: 0;
    right: 0;

    top: 125px;

    height: 150px;

    background:
        repeating-linear-gradient(
            0deg,
            transparent 0,
            transparent 12px,
            rgba(190, 205, 210, 0.08) 12px,
            rgba(190, 205, 210, 0.08) 22px
        );

    border-top: 1px solid #263d47;
    border-bottom: 1px solid #263d47;

    pointer-events: none;
}

.road-line {
    position: absolute;

    left: 0;

    width: 100%;
    height: 1px;

    background: #55707b;

    opacity: 0.25;
}

.line-1 {
    top: 33%;
}

.line-2 {
    top: 66%;
}

#player {
    position: absolute;

    left: 20px;
    bottom: 20px;

    width: 18px;
    height: 18px;

    background: #e4edf0;

    border: 2px solid #7c96a0;

    z-index: 20;

    box-shadow:
        0 0 10px rgba(190, 215, 225, 0.45);

    transform: rotate(45deg);
}

#player::after {
    content: "";

    position: absolute;

    width: 5px;
    height: 5px;

    top: 4px;
    left: 4px;

    background: #536b76;
}

#finish {
    position: absolute;

    left: 0;
    top: 0;

    width: 100%;
    height: 42px;

    display: flex;

    align-items: center;
    justify-content: center;

    background: #0e171c;

    border-bottom: 2px solid #536c77;

    color: #91a7b0;

    font-family: monospace;

    font-size: 10px;

    letter-spacing: 4px;

    z-index: 6;
}

#finish::before {
    content: "↑";

    position: absolute;

    left: 20px;
    top: 10px;

    font-size: 15px;
}

.obstacle,
.moving-obstacle {
    position: absolute;

    width: 42px;
    height: 24px;

    background: #10191e;

    border: 1px solid #657d87;

    z-index: 15;
}

.obstacle::before,
.moving-obstacle::before {
    content: "///";

    position: absolute;

    left: 6px;
    top: 3px;

    color: #667f89;

    font-family: monospace;

    font-size: 11px;
}

#gameMessage {
    min-height: 18px;

    margin-top: 20px;

    color: #8199a3;

    font-family: monospace;

    font-size: 10px;

    letter-spacing: 2px;
}

#startGameBtn {
    margin-top: 15px;

    padding: 11px 24px;

    background: #0b1318;

    border: 1px solid #536d78;

    color: #c7d5da;

    font-family: monospace;

    font-size: 10px;

    letter-spacing: 2px;
}


/* OTHER STAGES */

.mini-stage {
    min-height: 300px;
}

.mini-stage h2 {
    margin-top: 25px;

    color: #dce7ed;

    font-family: monospace;

    font-size: clamp(28px, 5vw, 48px);

    letter-spacing: 3px;
}

.stage-text {
    max-width: 650px;

    margin-top: 15px;

    color: #788c96;

    font-family: monospace;

    font-size: 11px;

    line-height: 1.8;
}

.puzzle-box {
    width: min(650px, 100%);

    margin-top: 40px;

    padding: 32px;

    background:
        linear-gradient(
            135deg,
            rgba(10, 20, 28, 0.9),
            rgba(5, 10, 14, 0.95)
        );

    border: 1px solid #2c424d;

    box-shadow:
        10px 10px 0 rgba(17, 28, 36, 0.5);
}

.jumble-words {
    margin: 32px 0;

    padding: 20px;

    background: #060a0d;

    border: 1px solid #263944;

    color: #d4e0e5;

    font-family: monospace;

    font-size: 19px;

    letter-spacing: 3px;

    text-align: center;
}

.attempt-info {
    margin-top: 16px;

    color: #536d78;

    font-family: monospace;

    font-size: 10px;

    letter-spacing: 2px;
}

.attempt-info b {
    color: #c8d6dc;
}


/* HIDDEN STAGE */

#hidden-stage {
    min-height: 350px;
}

#hidden-message-box {
    position: relative;

    width: min(600px, 100%);

    min-height: 140px;

    margin-top: 45px;

    display: flex;

    align-items: center;
    justify-content: center;

    background: #05090c;

    border: 1px solid #263b45;

    overflow: hidden;
}

#hidden-message-box::before {
    content: "";

    position: absolute;

    inset: 0;

    background:
        repeating-linear-gradient(
            0deg,
            transparent,
            transparent 5px,
            rgba(170, 200, 210, 0.025) 6px
        );
}

#hidden-message {
    margin: 0;

    color: #91a7b0;

    font-family: monospace;

    font-size: 18px;

    letter-spacing: 4px;

    text-align: center;

    opacity: 0;

    transition: opacity 0.2s;
}

#hiddenContinueBtn {
    margin-top: 25px;
}


/* MEMORY */

#memory-stage {
    min-height: 400px;
}

.memory-stats {
    margin-top: 22px;

    color: #607887;

    font-family: monospace;

    font-size: 10px;

    letter-spacing: 2px;
}

.memory-stats b {
    color: #d7e3e8;
}

#memory-board {
    width: min(560px, 100%);

    margin-top: 32px;

    display: grid;

    grid-template-columns: repeat(4, 1fr);

    gap: 10px;
}

.memory-card {
    width: 100%;

    aspect-ratio: 1;

    margin: 0;
    padding: 0;

    background: #0a1218;

    border: 1px solid #38515e;

    border-radius: 0;

    color: #9db0b9;

    font-family: monospace;

    font-size: 25px;

    transition: 0.2s;
}

.memory-card:hover {
    background: #14232c;

    border-color: #78909b;
}

.memory-card.flipped {
    background: #172831;

    border-color: #8198a2;

    color: #dce7ed;
}

.memory-card.matched {
    background: #0d1b21;

    border-color: #536d78;

    color: #9fb4be;

    cursor: default;
}

#memoryMessage {
    min-height: 20px;

    margin-top: 20px;

    color: #7f98a3;

    font-family: monospace;

    font-size: 10px;

    letter-spacing: 2px;
}


/* FINAL */

#signal03-final {
    min-height: 300px;

    padding-bottom: 80px;
}

.final-text {
    max-width: 650px;

    margin-top: 18px;

    color: #82919b;

    font-family: monospace;

    font-size: 12px;

    line-height: 1.8;
}

.final-box {
    width: min(650px, 100%);

    margin-top: 45px;

    padding: 38px;

    background:
        linear-gradient(
            135deg,
            rgba(15, 29, 38, 0.92),
            rgba(5, 10, 14, 0.96)
        );

    border: 1px solid #425b67;

    box-shadow:
        12px 12px 0 rgba(18, 29, 38, 0.5);
}

.final-status {
    margin-top: 28px;

    color: #dce7ed;

    font-family: monospace;

    font-size: clamp(28px, 5vw, 48px);

    letter-spacing: 5px;
}

.final-subtext {
    margin-top: 18px;

    color: #617984;

    font-family: monospace;

    font-size: 9px;

    letter-spacing: 3px;
}


/* MOBILE */

@media (max-width: 600px) {

    body {
        padding: 10px;
    }

    .terminal {
        margin: 15px auto;
        padding: 28px 20px;
    }

    .terminal h1 {
        font-size: 42px;
        letter-spacing: 4px;
    }

    .signal {
        padding: 25px 20px;
    }

    .terminal input {
        width: 100%;
    }

    .terminal button {
        width: 100%;

        margin-left: 0;
        margin-top: 10px;
    }

    .signal-02 {
        margin: 15px auto;
        padding: 30px 22px;
    }

    .signal-02 h1 {
        font-size: 38px;
    }

    .signal-02::after {
        display: none;
    }

    .signal-03 {
        padding: 25px 18px 70px;
    }

    .signal-03::after {
        display: none;
    }

    .signal-03 h1 {
        margin-top: 70px;

        font-size: 54px;

        letter-spacing: -3px;
    }

    .signal-03 .signal-box {
        margin-top: 55px;

        padding: 28px 21px;

        box-shadow:
            9px 9px 0 rgba(15, 25, 32, 0.7);
    }

    .signal-03 .riddle {
        font-size: 16px;
    }

    .signal-03 button {
        width: 100%;
    }

    #equation-area,
    #equation2-area,
    #location-area,
    .mini-stage,
    #memory-stage,
    #signal03-final {
        margin-top: 80px;
    }

    #location-area {
        padding: 30px 20px;
    }

    #location-area .message:nth-child(2) {
        font-size: 38px;
        letter-spacing: 4px;
    }

    .game-area {
        margin-top: 85px;
    }

    .game-stats {
        width: 100%;

        justify-content: space-between;
    }

    #game-board {
        height: 420px;
    }

    .puzzle-box {
        padding: 25px 20px;
    }

    .jumble-words {
        font-size: 15px;
        line-height: 1.7;
    }

    #memory-board {
        grid-template-columns: repeat(2, 1fr);

        max-width: 330px;
    }

    .final-box {
        padding: 28px 22px;
    }
}

.signal4-reveal {
    display: none;
    margin-top: 35px;
    padding: 20px;
    border-top: 1px solid #263746;
    line-height: 1.8;
}

.signal4-reveal .dim {
    color: #526575;
}

.signal4-button {
    display: inline-block;
    margin-top: 20px;
    padding: 12px 18px;
    border: 1px solid #344957;
    background: #0c1721;
    color: #9eb1bf;
    text-decoration: none;
    font-family: "Courier New", monospace;
}