diff --git a/src/components/OnThisDay.astro b/src/components/OnThisDay.astro
index 70581d9..dabf21a 100644
--- a/src/components/OnThisDay.astro
+++ b/src/components/OnThisDay.astro
@@ -1,16 +1,26 @@
 <section class="on-this-day-band" aria-labelledby="on-this-day-title">
   <div class="section-inner on-this-day-shell" data-on-this-day>
-    <div class="memory-date-card" aria-hidden="true">
-      <span data-memory-month>今日</span>
-      <strong data-memory-day>--</strong>
-      <small>北京时间</small>
+    <div class="memory-calendar" aria-label="记忆日历">
+      <div class="memory-calendar-head">
+        <div class="memory-calendar-nav">
+          <button type="button" data-calendar-previous aria-label="上一个月">←</button>
+          <strong data-calendar-label aria-live="polite">本月</strong>
+          <button type="button" data-calendar-next aria-label="下一个月">→</button>
+        </div>
+        <button class="memory-calendar-today" type="button" data-calendar-today>回到今天</button>
+      </div>
+      <div class="memory-calendar-weekdays" aria-hidden="true">
+        <span>日</span><span>一</span><span>二</span><span>三</span><span>四</span><span>五</span><span>六</span>
+      </div>
+      <div class="memory-calendar-grid" data-calendar-grid></div>
+      <p class="memory-calendar-legend"><span aria-hidden="true"></span>圆点表示这一天收录了班级记忆</p>
     </div>
 
     <div class="on-this-day-content">
       <div class="on-this-day-heading">
         <div>
           <p class="eyebrow">ON THIS DAY · 那年今日</p>
-          <h2 id="on-this-day-title">今天，记忆翻到了这一页</h2>
+          <h2 id="on-this-day-title" data-memory-title>今天，记忆翻到了这一页</h2>
         </div>
         <p data-memory-summary aria-live="polite">正在寻找同月同日的班级记忆……</p>
       </div>
@@ -50,84 +60,200 @@
       day: "numeric"
     }).formatToParts(new Date());
     const dateValues = Object.fromEntries(dateParts.map((part) => [part.type, part.value]));
-    const month = Number(dateValues.month);
-    const day = Number(dateValues.day);
+    const todayMonth = Number(dateValues.month);
+    const todayDay = Number(dateValues.day);
     const currentYear = Number(dateValues.year);
-    const monthDay = `${String(month).padStart(2, "0")}-${String(day).padStart(2, "0")}`;
-    const matches = onThisDayMemories.filter((memory) => memory.monthDay === monthDay);
-    const visibleMatches = matches.slice(0, 6);
+    let calendarYear = currentYear;
+    let calendarMonth = todayMonth;
+    let selectedMonth = todayMonth;
+    let selectedDay = todayDay;
 
-    const monthLabel = root.querySelector<HTMLElement>("[data-memory-month]");
-    const dayLabel = root.querySelector<HTMLElement>("[data-memory-day]");
+    const titleLabel = root.querySelector<HTMLElement>("[data-memory-title]");
     const summary = root.querySelector<HTMLElement>("[data-memory-summary]");
     const grid = root.querySelector<HTMLElement>("[data-memory-grid]");
     const empty = root.querySelector<HTMLElement>("[data-memory-empty]");
+    const calendarLabel = root.querySelector<HTMLElement>("[data-calendar-label]");
+    const calendarGrid = root.querySelector<HTMLElement>("[data-calendar-grid]");
+    const previousButton = root.querySelector<HTMLButtonElement>("[data-calendar-previous]");
+    const nextButton = root.querySelector<HTMLButtonElement>("[data-calendar-next]");
+    const todayButton = root.querySelector<HTMLButtonElement>("[data-calendar-today]");
 
-    if (monthLabel) monthLabel.textContent = `${month}月`;
-    if (dayLabel) dayLabel.textContent = String(day).padStart(2, "0");
+    const getMonthDay = (month: number, day: number) =>
+      `${String(month).padStart(2, "0")}-${String(day).padStart(2, "0")}`;
 
-    if (summary) {
-      summary.textContent = matches.length
-        ? `${month}月${day}日，找到了 ${matches.length} 条跨越不同年份的班级记忆。`
-        : `${month}月${day}日，今天暂时没有同月同日的记录。`;
-    }
+    const getMemories = (month: number, day: number) => {
+      const monthDay = getMonthDay(month, day);
+      return onThisDayMemories.filter((memory) => memory.monthDay === monthDay);
+    };
+
+    const renderMemories = (month: number, day: number) => {
+      selectedMonth = month;
+      selectedDay = day;
+      const matches = getMemories(month, day);
+      const visibleMatches = matches.slice(0, 6);
+      const isToday = month === todayMonth && day === todayDay;
+
+      if (titleLabel) {
+        titleLabel.textContent = isToday
+          ? "今天，记忆翻到了这一页"
+          : `${month}月${day}日，记忆翻到了这一页`;
+      }
+
+      if (summary) {
+        summary.textContent = matches.length
+          ? `${month}月${day}日，找到了 ${matches.length} 条跨越不同年份的班级记忆。`
+          : `${month}月${day}日，暂时没有同月同日的记录。`;
+      }
+
+      if (grid) {
+        const fragment = document.createDocumentFragment();
+
+        visibleMatches.forEach((memory) => {
+          const card = document.createElement("a");
+          card.className = `memory-card memory-card-${memory.kind}`;
+          card.href = memory.href;
+          card.setAttribute("aria-label", `${memory.year}年${memory.kindLabel}：${memory.title}`);
+          if (memory.external) {
+            card.target = "_blank";
+            card.rel = "noreferrer";
+          }
+
+          if (memory.image) {
+            const image = document.createElement("img");
+            image.src = memory.image;
+            image.alt = "";
+            image.loading = "lazy";
+            card.append(image);
+          } else {
+            const visual = document.createElement("span");
+            visual.className = "memory-card-visual";
+            visual.setAttribute("aria-hidden", "true");
+            visual.textContent = "记";
+            card.append(visual);
+          }
+
+          const copy = document.createElement("span");
+          copy.className = "memory-card-copy";
+
+          const meta = document.createElement("span");
+          meta.className = "memory-card-meta";
+          const yearsAgo = currentYear - memory.year;
+          meta.textContent = `${memory.year}年 · ${yearsAgo > 0 ? `${yearsAgo}年前 · ` : ""}${memory.kindLabel}`;
+
+          const title = document.createElement("strong");
+          title.textContent = memory.title;
+
+          const text = document.createElement("span");
+          text.className = "memory-card-text";
+          text.textContent = memory.text;
+
+          const action = document.createElement("span");
+          action.className = "memory-card-action";
+          action.textContent = memory.external ? "阅读旧文章 ↗" : "翻开这段记忆 →";
+
+          copy.append(meta, title, text, action);
+          card.append(copy);
+          fragment.append(card);
+        });
+
+        grid.replaceChildren(fragment);
+        grid.hidden = matches.length === 0;
+        grid.setAttribute("aria-busy", "false");
+      }
+
+      if (empty) empty.hidden = matches.length > 0;
+    };
+
+    const renderCalendar = () => {
+      if (calendarLabel) calendarLabel.textContent = `${calendarYear}年${calendarMonth}月`;
+      if (!calendarGrid) return;
 
-    if (grid) {
       const fragment = document.createDocumentFragment();
+      const firstWeekday = new Date(calendarYear, calendarMonth - 1, 1).getDay();
+      const daysInMonth = new Date(calendarYear, calendarMonth, 0).getDate();
 
-      visibleMatches.forEach((memory) => {
-        const card = document.createElement("a");
-        card.className = `memory-card memory-card-${memory.kind}`;
-        card.href = memory.href;
-        card.setAttribute("aria-label", `${memory.year}年${memory.kindLabel}：${memory.title}`);
-        if (memory.external) {
-          card.target = "_blank";
-          card.rel = "noreferrer";
+      for (let index = 0; index < firstWeekday; index += 1) {
+        const spacer = document.createElement("span");
+        spacer.className = "memory-calendar-spacer";
+        spacer.setAttribute("aria-hidden", "true");
+        fragment.append(spacer);
+      }
+
+      for (let day = 1; day <= daysInMonth; day += 1) {
+        const matches = getMemories(calendarMonth, day);
+        const button = document.createElement("button");
+        button.type = "button";
+        button.dataset.calendarDay = String(day);
+        button.className = "memory-calendar-day";
+        button.setAttribute(
+          "aria-label",
+          matches.length ? `${calendarMonth}月${day}日，有${matches.length}条记忆` : `${calendarMonth}月${day}日`
+        );
+
+        if (matches.length) {
+          button.classList.add("has-memory");
+          button.dataset.memoryCount = String(matches.length);
+        }
+        if (calendarMonth === selectedMonth && day === selectedDay) {
+          button.classList.add("is-selected");
+          button.setAttribute("aria-pressed", "true");
+        }
+        if (calendarYear === currentYear && calendarMonth === todayMonth && day === todayDay) {
+          button.classList.add("is-today");
         }
 
-        if (memory.image) {
-          const image = document.createElement("img");
-          image.src = memory.image;
-          image.alt = "";
-          image.loading = "lazy";
-          card.append(image);
-        } else {
-          const visual = document.createElement("span");
-          visual.className = "memory-card-visual";
-          visual.setAttribute("aria-hidden", "true");
-          visual.textContent = "记";
-          card.append(visual);
+        const number = document.createElement("span");
+        number.textContent = String(day);
+        button.append(number);
+
+        if (matches.length) {
+          const dot = document.createElement("i");
+          dot.setAttribute("aria-hidden", "true");
+          button.append(dot);
         }
 
-        const copy = document.createElement("span");
-        copy.className = "memory-card-copy";
+        fragment.append(button);
+      }
 
-        const meta = document.createElement("span");
-        meta.className = "memory-card-meta";
-        const yearsAgo = currentYear - memory.year;
-        meta.textContent = `${memory.year}年 · ${yearsAgo > 0 ? `${yearsAgo}年前 · ` : ""}${memory.kindLabel}`;
+      calendarGrid.replaceChildren(fragment);
+    };
 
-        const title = document.createElement("strong");
-        title.textContent = memory.title;
+    calendarGrid?.addEventListener("click", (event) => {
+      const target = event.target;
+      if (!(target instanceof Element)) return;
+      const button = target.closest<HTMLButtonElement>("[data-calendar-day]");
+      if (!button) return;
 
-        const text = document.createElement("span");
-        text.className = "memory-card-text";
-        text.textContent = memory.text;
+      renderMemories(calendarMonth, Number(button.dataset.calendarDay));
+      renderCalendar();
+    });
 
-        const action = document.createElement("span");
-        action.className = "memory-card-action";
-        action.textContent = memory.external ? "阅读旧文章 ↗" : "翻开这段记忆 →";
+    previousButton?.addEventListener("click", () => {
+      calendarMonth -= 1;
+      if (calendarMonth === 0) {
+        calendarMonth = 12;
+        calendarYear -= 1;
+      }
+      renderCalendar();
+    });
 
-        copy.append(meta, title, text, action);
-        card.append(copy);
-        fragment.append(card);
-      });
+    nextButton?.addEventListener("click", () => {
+      calendarMonth += 1;
+      if (calendarMonth === 13) {
+        calendarMonth = 1;
+        calendarYear += 1;
+      }
+      renderCalendar();
+    });
 
-      grid.replaceChildren(fragment);
-      grid.hidden = matches.length === 0;
-      grid.setAttribute("aria-busy", "false");
-    }
+    todayButton?.addEventListener("click", () => {
+      calendarYear = currentYear;
+      calendarMonth = todayMonth;
+      renderMemories(todayMonth, todayDay);
+      renderCalendar();
+    });
 
-    if (empty) empty.hidden = matches.length > 0;
+    renderMemories(todayMonth, todayDay);
+    renderCalendar();
   }
 </script>
diff --git a/src/styles/global.css b/src/styles/global.css
index 97354a6..4763916 100644
--- a/src/styles/global.css
+++ b/src/styles/global.css
@@ -225,56 +225,16 @@ h1 {
   position: relative;
   z-index: 1;
   display: grid;
-  grid-template-columns: 150px minmax(0, 1fr);
+  grid-template-columns: minmax(280px, 1fr) minmax(0, 2fr);
   gap: clamp(28px, 5vw, 64px);
   align-items: start;
 }
 
-.memory-date-card {
-  position: sticky;
-  top: 26px;
-  overflow: hidden;
-  border: 1px solid rgba(55, 109, 90, 0.2);
-  border-radius: 14px;
-  background: #fffdf7;
-  box-shadow: 0 18px 42px rgba(39, 55, 52, 0.11);
-  text-align: center;
-}
-
-.memory-date-card span,
-.memory-date-card small {
-  display: block;
-}
-
-.memory-date-card span {
-  padding: 8px 12px;
-  background: var(--green);
-  color: #fffdf7;
-  font-size: 14px;
-  font-weight: 800;
-}
-
-.memory-date-card strong {
-  display: block;
-  padding: 12px 12px 2px;
-  color: var(--ink);
-  font-family: Georgia, "Times New Roman", serif;
-  font-size: 62px;
-  line-height: 1;
-}
-
-.memory-date-card small {
-  padding: 8px 12px 13px;
-  color: var(--muted);
-  font-size: 11px;
-  letter-spacing: 0.08em;
-}
-
 .on-this-day-heading {
   display: grid;
-  grid-template-columns: minmax(0, 1fr) minmax(240px, 0.8fr);
-  gap: clamp(20px, 4vw, 52px);
-  align-items: end;
+  grid-template-columns: 1fr;
+  gap: 12px;
+  align-items: start;
   margin-bottom: 30px;
 }
 
@@ -287,6 +247,162 @@ h1 {
   color: var(--muted);
 }
 
+.memory-calendar {
+  position: sticky;
+  top: 26px;
+  padding: 18px;
+  border: 1px solid rgba(31, 43, 42, 0.12);
+  border-radius: 14px;
+  background: rgba(255, 255, 255, 0.72);
+  box-shadow: 0 8px 28px rgba(39, 55, 52, 0.06);
+  backdrop-filter: blur(10px);
+}
+
+.memory-calendar-head,
+.memory-calendar-nav {
+  display: flex;
+  align-items: center;
+}
+
+.memory-calendar-head {
+  display: grid;
+  gap: 10px;
+  margin-bottom: 16px;
+}
+
+.memory-calendar-nav {
+  justify-content: space-between;
+  gap: 10px;
+}
+
+.memory-calendar-nav strong {
+  min-width: 126px;
+  text-align: center;
+  font-size: 18px;
+}
+
+.memory-calendar-nav button,
+.memory-calendar-today {
+  min-height: 38px;
+  border: 1px solid var(--line);
+  background: #fffdf7;
+  color: var(--ink);
+  font: inherit;
+  font-weight: 800;
+  cursor: pointer;
+  transition: border-color 160ms ease, background 160ms ease, color 160ms ease;
+}
+
+.memory-calendar-nav button {
+  width: 38px;
+  padding: 0;
+  border-radius: 50%;
+}
+
+.memory-calendar-today {
+  width: 100%;
+  padding: 7px 13px;
+  border-radius: 999px;
+  color: var(--green);
+  font-size: 13px;
+}
+
+.memory-calendar-nav button:hover,
+.memory-calendar-today:hover {
+  border-color: var(--green);
+  background: var(--green);
+  color: #fff;
+}
+
+.memory-calendar-weekdays,
+.memory-calendar-grid {
+  display: grid;
+  grid-template-columns: repeat(7, minmax(0, 1fr));
+  gap: 7px;
+}
+
+.memory-calendar-weekdays {
+  margin-bottom: 7px;
+  color: var(--muted);
+  text-align: center;
+  font-size: 12px;
+  font-weight: 800;
+}
+
+.memory-calendar-day,
+.memory-calendar-spacer {
+  min-width: 0;
+  aspect-ratio: 1.45;
+}
+
+.memory-calendar-day {
+  position: relative;
+  display: grid;
+  place-items: center;
+  align-content: center;
+  gap: 3px;
+  padding: 4px;
+  border: 1px solid transparent;
+  border-radius: 9px;
+  background: rgba(244, 247, 238, 0.72);
+  color: var(--muted);
+  font: inherit;
+  font-size: 13px;
+  cursor: pointer;
+  transition: transform 150ms ease, border-color 150ms ease, background 150ms ease, color 150ms ease;
+}
+
+.memory-calendar-day:hover {
+  transform: translateY(-1px);
+  border-color: rgba(55, 109, 90, 0.3);
+  color: var(--green);
+  background: #fff;
+}
+
+.memory-calendar-day.has-memory {
+  color: var(--ink);
+  background: rgba(232, 168, 76, 0.12);
+  font-weight: 800;
+}
+
+.memory-calendar-day i {
+  width: 5px;
+  height: 5px;
+  border-radius: 50%;
+  background: var(--coral);
+}
+
+.memory-calendar-day.is-today {
+  border-color: rgba(55, 109, 90, 0.55);
+}
+
+.memory-calendar-day.is-selected {
+  border-color: var(--green);
+  background: var(--green);
+  color: #fffdf7;
+  box-shadow: 0 6px 16px rgba(55, 109, 90, 0.2);
+}
+
+.memory-calendar-day.is-selected i {
+  background: #f3cf8b;
+}
+
+.memory-calendar-legend {
+  display: flex;
+  align-items: center;
+  gap: 7px;
+  margin: 12px 0 0;
+  color: var(--muted);
+  font-size: 12px;
+}
+
+.memory-calendar-legend > span {
+  width: 6px;
+  height: 6px;
+  border-radius: 50%;
+  background: var(--coral);
+}
+
 .memory-grid {
   display: grid;
   grid-template-columns: repeat(2, minmax(0, 1fr));
@@ -296,7 +412,7 @@ h1 {
 .memory-card {
   min-height: 190px;
   display: grid;
-  grid-template-columns: 150px minmax(0, 1fr);
+  grid-template-columns: 120px minmax(0, 1fr);
   overflow: hidden;
   border: 1px solid rgba(31, 43, 42, 0.12);
   border-radius: 12px;
@@ -2366,7 +2482,21 @@ h2 {
   transform: translate(-50%, 0);
 }
 
+@media (max-width: 1040px) and (min-width: 821px) {
+  .memory-grid {
+    grid-template-columns: 1fr;
+  }
+
+  .memory-calendar {
+    position: static;
+  }
+}
+
 @media (max-width: 820px) {
+  .memory-calendar {
+    position: static;
+  }
+
   body:has(.score-sidebar) {
     padding-bottom: 86px;
   }
@@ -2659,6 +2789,34 @@ h2 {
     min-height: 0;
   }
 
+  .memory-calendar {
+    margin-inline: -4px;
+    padding: 13px 9px;
+  }
+
+  .memory-calendar-head {
+    align-items: stretch;
+    flex-direction: column;
+  }
+
+  .memory-calendar-nav {
+    justify-content: space-between;
+  }
+
+  .memory-calendar-today {
+    width: 100%;
+  }
+
+  .memory-calendar-weekdays,
+  .memory-calendar-grid {
+    gap: 4px;
+  }
+
+  .memory-calendar-day,
+  .memory-calendar-spacer {
+    aspect-ratio: 1;
+  }
+
   .hero-actions {
     display: grid;
   }
@@ -2673,15 +2831,6 @@ h2 {
     min-height: auto;
   }
 
-  .memory-date-card {
-    position: static;
-    width: 104px;
-  }
-
-  .memory-date-card strong {
-    font-size: 48px;
-  }
-
   .memory-grid {
     grid-template-columns: 1fr;
   }