:root {
    --bg: #efeae1;
    --ink: #1d1b18;
    --muted: #7b756b;
    --body: #e4ddd0;          /* корпус калькулятора */
    --screen: #1d1b18;
    --screen-ink: #f3efe7;
    --screen-dim: #8c867a;
    --key: #f7f3ea;
    --key-edge: #c9c0ae;      /* "толщина" клавиши */
    --fn: #d8cfbd;
    --fn-edge: #b3a88f;
    --accent: #ff5b2e;
    --accent-edge: #b83d18;
    --accent-ink: #fff;
    --shadow: rgba(60, 45, 20, 0.18);
}

[data-theme="mint"] {
    --bg: #e6efe9; --body: #d3e3d9; --key: #f4faf6; --key-edge: #b4cdbf;
    --fn: #c3d8cb; --fn-edge: #9cb9a9; --accent: #1fae7a; --accent-edge: #12744f;
    --muted: #6b7f74;
}
[data-theme="lilac"] {
    --bg: #ece9f6; --body: #dcd7f0; --key: #f7f5fd; --key-edge: #bdb5e0;
    --fn: #cbc4e8; --fn-edge: #a59bd3; --accent: #7a5cff; --accent-edge: #4a33b8;
    --muted: #756f90;
}
[data-theme="night"] {
    --bg: #141414; --ink: #f1f1f1; --muted: #8a8a8a; --body: #232323;
    --screen: #0c0c0c; --screen-ink: #f1f1f1; --screen-dim: #6f6f6f;
    --key: #333; --key-edge: #131313; --fn: #2a2a2a; --fn-edge: #0e0e0e;
    --accent: #ffd23f; --accent-edge: #a88710; --accent-ink: #1a1a1a;
    --shadow: rgba(0, 0, 0, 0.6);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
    background: var(--bg);
    color: var(--ink);
    font-family: 'Space Grotesk', system-ui, sans-serif;
    line-height: 1.6;
    transition: background .5s ease, color .5s ease;
    -webkit-font-smoothing: antialiased;
}

em { font-style: normal; color: var(--accent); transition: color .5s ease; }

/* ===== Шапка ===== */
.top {
    display: flex; justify-content: space-between; align-items: center;
    padding: 1.6rem 6%; max-width: 1200px; margin: 0 auto;
}
.brand { font-weight: 700; font-size: 1.5rem; letter-spacing: -1px; color: var(--ink); text-decoration: none; }
.brand span { color: var(--accent); }
.top nav { display: flex; gap: 2rem; }
.top nav a { color: var(--muted); text-decoration: none; font-size: .95rem; transition: color .2s; }
.top nav a:hover { color: var(--ink); }

/* ===== Hero ===== */
.hero {
    max-width: 1200px; margin: 0 auto; padding: 3rem 6% 6rem;
    display: grid; grid-template-columns: 1.1fr 1fr; gap: 4rem; align-items: center;
}
h1 { font-size: clamp(2.8rem, 6vw, 5rem); line-height: 1.02; letter-spacing: -2px; font-weight: 700; margin-bottom: 2.2rem; }
.eyebrow {
    font-family: 'JetBrains Mono', monospace; font-size: .8rem; letter-spacing: 2px;
    text-transform: uppercase; color: var(--muted); margin-bottom: 1.2rem;
}

/* ===== Переключатель тем ===== */
.themes { display: flex; align-items: center; gap: .9rem; }
.themes-label { font-family: 'JetBrains Mono', monospace; font-size: .8rem; color: var(--muted); text-transform: uppercase; letter-spacing: 1px; margin-right: .3rem; }
.swatch {
    width: 34px; height: 34px; border-radius: 50%; border: 0; cursor: pointer;
    background: var(--c); position: relative;
    box-shadow: inset 0 -3px 0 rgba(0,0,0,.2), 0 2px 6px var(--shadow);
    transition: transform .2s cubic-bezier(.34,1.56,.64,1);
}
.swatch:hover { transform: scale(1.15); }
.swatch[aria-checked="true"]::after {
    content: ''; position: absolute; inset: -6px; border-radius: 50%;
    border: 2px solid var(--ink);
}

/* ===== Корпус калькулятора ===== */
.device {
    background: var(--body);
    border-radius: 34px;
    padding: 1.4rem 1.4rem 1rem;
    max-width: 380px; width: 100%; justify-self: center;
    box-shadow:
        inset 0 2px 0 rgba(255,255,255,.5),
        0 3px 0 var(--key-edge),
        0 40px 70px -20px var(--shadow);
    transform: rotate(1.5deg);
    transition: transform .5s cubic-bezier(.34,1.56,.64,1), background .5s ease;
}
.device:hover { transform: rotate(0deg); }

.screen {
    background: var(--screen); color: var(--screen-ink);
    border-radius: 20px; padding: 1rem 1.2rem 1.1rem;
    min-height: 168px; display: flex; flex-direction: column; justify-content: flex-end;
    text-align: right; margin-bottom: 1.3rem; overflow: hidden;
    box-shadow: inset 0 4px 14px rgba(0,0,0,.5);
    font-family: 'JetBrains Mono', monospace;
}
.tape { list-style: none; font-size: .78rem; color: var(--screen-dim); margin-bottom: auto; max-height: 56px; overflow: hidden; }
.tape li { cursor: pointer; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; transition: color .2s; }
.tape li:hover { color: var(--accent); }
.expr { font-size: 1.9rem; font-weight: 600; word-break: break-all; line-height: 1.2; min-height: 2.3rem; }
.expr.small { font-size: 1.35rem; }
.result { font-size: 1.05rem; color: var(--accent); min-height: 1.6rem; transition: color .5s ease; }
.screen.error .expr { color: var(--accent); animation: shake .35s; }
@keyframes shake { 25% { transform: translateX(-6px); } 75% { transform: translateX(6px); } }

/* ===== Кнопки ===== */
.pad { display: grid; grid-template-columns: repeat(4, 1fr); gap: .8rem; }

.key {
    --face: var(--key); --edge: var(--key-edge); --lift: 6px;
    font-family: 'Space Grotesk', sans-serif; font-size: 1.45rem; font-weight: 500; color: var(--ink);
    aspect-ratio: 1 / 1; border: 0; cursor: pointer; border-radius: 22px;
    background: var(--face);
    box-shadow: 0 var(--lift) 0 var(--edge), 0 calc(var(--lift) + 8px) 14px var(--shadow);
    transform: translateY(0);
    transition: transform .09s ease, box-shadow .09s ease, background .5s ease, color .5s ease;
    -webkit-tap-highlight-color: transparent; user-select: none;
}
.key:hover { filter: brightness(1.04); }
.key:active, .key.pressed {
    transform: translateY(var(--lift));
    box-shadow: 0 0 0 var(--edge), 0 2px 4px var(--shadow);
}
.key:focus-visible { outline: 3px solid var(--accent); outline-offset: 3px; }

.key.fn { --face: var(--fn); --edge: var(--fn-edge); font-size: 1.15rem; }

/* операторы — круглые «кнопки-капли» */
.key.op {
    --face: var(--ink); --edge: color-mix(in srgb, var(--ink) 55%, #000);
    color: var(--bg); border-radius: 50%; font-size: 1.7rem;
}
[data-theme="night"] .key.op { --face: #f1f1f1; --edge: #8d8d8d; color: #141414; }
.key.op.active { --face: var(--accent); --edge: var(--accent-edge); color: var(--accent-ink); }

/* «=» — акцентная, чуть пульсирует */
.key.eq {
    --face: var(--accent); --edge: var(--accent-edge); color: var(--accent-ink);
    border-radius: 22px 22px 22px 50%; font-size: 1.9rem;
}
.key.eq::before {
    content: ''; position: absolute; inset: 0; border-radius: inherit; pointer-events: none;
}
.key.eq { position: relative; animation: breathe 2.6s ease-in-out infinite; }
@keyframes breathe {
    0%, 100% { filter: brightness(1); }
    50% { filter: brightness(1.12); }
}

.sound {
    display: block; margin: 1.2rem auto .3rem; background: none; border: 0; cursor: pointer;
    font-family: 'JetBrains Mono', monospace; font-size: .72rem; letter-spacing: 1px;
    color: var(--muted); text-transform: uppercase;
}
.sound:hover { color: var(--ink); }

/* ===== Фичи ===== */
.features, .keys-sec { max-width: 1200px; margin: 0 auto; padding: 4rem 6%; }
h2 { font-size: clamp(1.9rem, 4vw, 3rem); letter-spacing: -1.5px; line-height: 1.1; margin-bottom: 2.5rem; }

/* ===== Bento ===== */
.bento { display: grid; grid-template-columns: repeat(6, 1fr); gap: 1.2rem; }
.tile {
    background: var(--body); border-radius: 30px; padding: 1.8rem; position: relative; overflow: hidden;
    box-shadow: 0 6px 0 var(--key-edge); display: flex; flex-direction: column; gap: .8rem;
    transition: background .5s ease;
}
.tile h3 { font-size: 1.5rem; letter-spacing: -.8px; line-height: 1.15; }
.tile p { color: var(--muted); font-size: .95rem; margin-top: auto; }
.num { font-family: 'JetBrains Mono', monospace; color: var(--accent); font-size: .78rem; text-transform: uppercase; letter-spacing: 1.5px; }
.t-press { grid-column: span 2; align-items: center; text-align: center; }
.t-live { grid-column: span 4; }
.t-tape { grid-column: span 3; }
.t-theme { grid-column: span 3; }
.t-press .num { align-self: flex-start; }

.bigkey {
    width: 130px; height: 130px; border: 0; border-radius: 38px; cursor: pointer; margin: .6rem 0 1.4rem;
    background: var(--accent); color: var(--accent-ink); font: 700 1.1rem 'JetBrains Mono', monospace; text-transform: uppercase; letter-spacing: 2px;
    box-shadow: 0 12px 0 var(--accent-edge), 0 24px 26px var(--shadow);
    transition: transform .09s, box-shadow .09s, background .5s;
}
.bigkey:active { transform: translateY(12px); box-shadow: 0 0 0 var(--accent-edge), 0 3px 6px var(--shadow); }
.t-press p b { color: var(--ink); font-family: 'JetBrains Mono', monospace; }

.liveinput { display: block; background: var(--screen); border-radius: 18px 18px 0 0; padding: .9rem 1.2rem 0; }
.liveinput input { display: block; width: 100%; background: none; border: 0; outline: 0; color: var(--screen-ink); font: 600 1.5rem 'JetBrains Mono', monospace; text-align: right; }
.liveout { margin-top: -.8rem; background: var(--screen); border-radius: 0 0 18px 18px; padding: 0 1.2rem 1rem; text-align: right; color: var(--accent); font: 600 1.1rem 'JetBrains Mono', monospace; min-height: 2.4rem; transition: color .5s; }
.liveinput:focus-within { outline: 2px solid var(--accent); outline-offset: 3px; }

.minitape { list-style: none; display: flex; flex-direction: column; gap: .5rem; }
.minitape li {
    display: flex; justify-content: space-between; gap: 1rem; padding: .7rem 1rem; cursor: pointer;
    background: var(--key); border-radius: 14px; box-shadow: 0 3px 0 var(--key-edge);
    font: 500 .9rem 'JetBrains Mono', monospace; animation: slidein .45s cubic-bezier(.34,1.56,.64,1);
    transition: transform .12s, box-shadow .12s;
}
.minitape li:active { transform: translateY(3px); box-shadow: 0 0 0 var(--key-edge); }
.minitape li b { color: var(--accent); font-weight: 600; }
@keyframes slidein { from { opacity: 0; transform: translateY(-14px) scale(.96); } }

.chips { display: grid; grid-template-columns: 1fr 1fr; gap: .7rem; }
.chips button {
    font: 600 .95rem 'Space Grotesk', sans-serif; color: var(--c); background: var(--b);
    border: 2px solid var(--c); border-radius: 16px; padding: 1rem; cursor: pointer;
    box-shadow: 0 4px 0 var(--c); transition: transform .09s, box-shadow .09s;
}
.chips button:hover { transform: translateY(-2px); box-shadow: 0 6px 0 var(--c); }
.chips button:active { transform: translateY(4px); box-shadow: 0 0 0 var(--c); }

/* ===== Клавиши ===== */
.hotkeys { list-style: none; display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 1rem; }
.hotkeys li { display: flex; align-items: center; gap: 1rem; }
kbd {
    font-family: 'JetBrains Mono', monospace; font-size: .9rem; font-weight: 600;
    background: var(--key); padding: .45rem .8rem; border-radius: 10px;
    box-shadow: 0 3px 0 var(--key-edge); white-space: nowrap;
}
.hotkeys span { color: var(--muted); font-size: .95rem; }

footer {
    max-width: 1200px; margin: 3rem auto 0; padding: 2rem 6% 3rem;
    display: flex; justify-content: space-between; color: var(--muted); font-size: .9rem;
    border-top: 1px solid color-mix(in srgb, var(--muted) 25%, transparent);
}
footer a { color: var(--muted); text-decoration: none; }
footer a:hover { color: var(--accent); }

/* ===== Адаптив ===== */
@media (max-width: 900px) {
    .hero { grid-template-columns: 1fr; gap: 3rem; padding-top: 1rem; }
    .device { transform: none; }
    .top nav { gap: 1.2rem; }
    .bento { grid-template-columns: 1fr; }
    .t-press, .t-live, .t-tape, .t-theme { grid-column: auto; }
}
@media (prefers-reduced-motion: reduce) {
    * { animation: none !important; transition-duration: .01ms !important; }
}